incrementer-iframe-messagechannel.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>A test page that messes with a given SharedArrayBuffer via MessageChannel</title>
<script src="test-incrementer.js"></script>

<script>
  const channel = new MessageChannel();
  window.parent.postMessage(channel.port2, '*', [channel.port2]);
  setupDestinationIncrementer(channel.port1, channel.port1);
</script>

chromium/third_party/blink/web_tests/external/wpt/html/infrastructure/safe-passing-of-structured-data/shared-array-buffers/resources/incrementer-iframe-messagechannel.html